1. Premature deaths due to drug use continue to be of major concern in Australia, despite recent reductions in the number of these deaths. This Information Paper is an update of information originally published in the article 'Drug-related Deaths' in the ABS publication Australian Social Trends, 2001 (cat. no. 4102.0).1 It presents data for drug-induced deaths registered in the years 1991 to 2001 (the latest year for which deaths data are available). Unless otherwise specified, this paper refers to deaths registered by the state and territory Registrars-General during the calendar years in question. For information on year of occurrence data see section 7. The paper incorporates changes to the ABS definition of drug-induced deaths, which were published in the Information Paper Drug-induced Deaths - A Guide to ABS Causes of Death Data (cat. no. 4809.0.55.001) .2

2. Results from the 2001 National Drug Strategy Household Survey indicate that an estimated 2.6 million Australians, or 16.9 % of people aged 14 years and over, had used illicit drugs in the previous 12 months.3 Cannabis was the most prevalent drug used (by 12.9% of total people in this age group), with the potentially more lethal illicit drugs being used by much smaller proportions of people. Amphetamines were used by 3.4% of people aged 14 years and over, ecstasy by 2.9% and heroin by less than 1%.

1.1 Definition - drug-induced deaths

3. ABS definitions relating to causes of death are based on the International Classification of Diseases, revision 10 (ICD-10). The ABS publication Drug-induced deaths - A Guide to ABS Causes of Death Data,defines drug-induced deaths as

"Any death where the underlying cause of death was due to:

An acute episode of poisoning or toxicity to drugs. Included are deaths from accidental overdoses due to misuse of drugs, intentional self-harm, assault and deaths undetermined as to intent.

An acute condition caused by drug use where the deceased person was identified as drug dependent.

4. The term 'drug' refers to substances classified as drugs, medicaments or biological substances under ICD-10 guidelines. These drugs may by used for medicinal or therapeutic purposes, or to produce a psychoactive effect. The term excludes alcohol, tobacco and volatile solvents (e.g. petrol)."

5. For ABS purposes, drug-induced deaths are defined by the following ICD-10 codes:

6. In addition, although not part of the ICD-10 itself, this paper classifies drug-induced deaths according to their intent. Accidental drug-induced deaths include ICD-10 codes X40-X44, F11-F16, F19 and F55. Suicide by drugs includes ICD-10 codes X60-X64. This paper also uses the term drug-induced deaths involving opioids to describe drug-induced deaths where opium (ICD-10 code T40.0), heroin (T40.1) other opiates, (such as morphine or codeine, T40.2), methadone (T40.3), other synthetic narcotics (such as pethidine, T40.4) or other and unspecified narcotics (T40.6) were mentioned on official records.

7. In 2001 there were 1,038 drug-induced deaths registered, constituting 0.8% of all deaths in that year (see summary table no. 3). This represented a fall of more than one-third from 1999, when drug-induced deaths registered in Australia peaked at 1,739 (1.4% of all registered deaths). Between 1999 and 2001 the standardised drug-induced death rate decreased by over 40%, from 9.1 to 5.3 registered deaths per 100,000 persons.

8. The decrease in drug-induced deaths was primarily related to a fall in deaths due to heroin use, particularly amongst men. In 1999 the standardised rate of drug-induced deaths involving opioids was 6.5 per 100,000 persons (9.8 males, 3.2 females). By 2001 this had fallen to 2.6 per 100,000 population (3.8 males, 1.5 females).

FIGURE 1 - DRUG-INDUCED DEATH RATES, Australia, 1991-2001

9. The reduction in the drug-induced death rate was not uniform across the states. Starting from a far higher level, the largest decreases were in New South Wales and Victoria. There were smaller decreases in Queensland, South Australia and Western Australia. As a result, the significant differences in the standardised drug-induced death rates between the larger states visible in 1999 have been substantially reduced. Rates for Tasmania, the Northern Territory or the Australian Capital Territory are not calculated and presented here for individual years, due to the small numbers of drug-induced deaths involved, and the unreliability of any comparisons that might be made.

10. Drug-induced deaths are usually the result of an unintentional overdose or the effects of prolonged misuse of drugs. This remained the case in 2001, despite a more substantial decrease in accidental deaths due to drugs than in the overall drug-induced death rate. Accidental drug-induced deaths fell from 7.3 per 100,000 persons in 1999 to 3.7 in 2001 (standardised figures).

11. The standardised accidental drug-induced death rate for males decreased from 10.9 deaths per 100,000 persons in 1999 to 5.0 in 2001. In comparison the corresponding rate for females fell from 3.8 to 2.3 deaths per 100,000 persons. Consequently, the large gap between the female and male rates observed in 1999 has narrowed considerably. The standardised male accidental drug-induced death rate is now around twice as high as the female rate.

FIGURE 3 - ACCIDENTAL DRUG-INDUCED DEATH RATES, Australia, 1991-2001

12. The use of heroin (an opioid) has been a focus of public debate on drug use during the past decade. Increased heroin use was largely responsible for the increase in accidental drug-induced deaths during the 1980s and 1990s. In 1999 opioids were involved in 77% of accidental drug-induced deaths. However, in 2001 this had declined to 58%. This fall was less pronounced amongst males (from 80% to 63%) than females (from 68% to 47%). In 1999 there were 1,084 accidental drug-induced deaths involving opioids (840 male, 244 female), but this fell to 413 in 2001 (304 male, 109 female). As an age standardised rate, accidental drug-induced deaths involving opioids fell from 5.6 deaths per 100,000 persons in 1999 (8.7 males, 2.6 females) to 2.1 in 2001 (3.2 males, 1.1 females). A fall in accidental drug-induced deaths involving opioids thus constituted the major contributor to the fall in the absolute number of drug-induced deaths (see figure 4).

13. This fall in deaths involving opioids seems to have been due to a shortage of heroin supply in Australia, also known as a 'heroin drought'. Results from the Illicit Drug Reporting System, administered by the National Drug and Alcohol Research Centre, indicate that "there was a dramatic reduction in the availability of heroin observed in all jurisdictions in which heroin had for some years been freely available" which "began in late 2000/early 2001, and was sustained throughout the first half of 2001".4 Furthermore, the shortage in supply seems to have resulted in decreased heroin usage. These findings have been corroborated by a study conducted by the NSW Bureau of Crime Statistics and Research.5 Declining heroin use was also detected by the 2001 National Drug Strategy Household Survey, with the percentage of respondents reporting heroin use in the last 12 months falling from 0.8% in 1998 to 0.2% in 2001.6 While the results of these studies should to be treated with some caution, due to the relatively small sample size of the surveys involved, taken together they offer strong evidence of a decrease in heroin usage. This would largely account for the fall in accidental drug-induced deaths.

14. In contrast to accidental drug-induced deaths, suicides involving drugs did not show any significant change between 1999 and 2001. The standardised death rate for suicides by drugs remained steady at 1.5 deaths per 100,000 persons. The relatively equal distribution of suicides by drugs between males and females also remained (see figure 5).

15. This stability in suicide rates by drugs was consistent with the overall suicide figures between 1999-2001. The standardised suicide rate for all methods for males fell slightly from 22 deaths per 100,000 persons in 1999 to 20 in 2001, while the corresponding rate for females remained steady at 5 deaths per 100,000 persons. Consequently, the proportion of all suicides using drugs increased only slightly for females between 1999-2001, from 24% to 26%, while remaining stable for males at 8%.

16. In 2001 there were 285 suicides by drugs, accounting for 12% of all suicides in that year. Drugs were used in 26% of the suicides of females, making it the second most common method after hanging and strangulation (38%). Drugs were used in 8% of suicides by males, making it the fourth most common method after hanging and strangulation (44%), exposure to gases (mostly carbon monoxide from motor vehicle exhaust) (21%) and firearms (13%).

17. The tendency of people to die from drug-induced causes varied according to age group. In addition, the age profile of people who died accidentally from drug-induced causes differed substantially from those who suicided using drugs.

18. In 2001, rates of accidental drug-induced deaths were highest among young adults, peaking at 8 deaths per 100,000 persons among both 25-29 and 30-34 year-olds. In 1999 the drug-induced deaths peaked amongst 25-29 year-olds alone.

19. Although there was some fluctuation in age-specific rates of suicide by drugs, they were relatively stable compared to accidental drug-induced deaths. In 2001 suicide by drugs peaked at 3.4 deaths per 100,000 persons amongst those aged 85 years and over. However, the rate was between 1 and 3 deaths per 100,000 persons for all ages between 20 and 84 years. The age profile of people committing suicide by drugs was also different to that of people using other methods. As a proportion of all suicides, drug suicides increased with age, with 15% of suicides of people aged over 50 years from drugs, compared with 7% for those aged less than thirty years.

20. Because of the pharmacological interactions between different drugs, using a mixture of drugs is more likely to result in adverse health effects, including death, than use of a single type of drug. For example, alcohol increases the effects of some drugs, and was present in 18% of accidental drug-induced deaths as a contributing factor, rather than as the drug that ultimately caused the death.

21. In 2001, opium, heroin and other opioids were involved in 36% of accidental drug-induced deaths, benzodiazepines were involved in 23% and other narcotics and hallucinogens were involved in 18%. Opium, heroin and other opioids were involved in the highest proportions of accidental drug-induced deaths of both males and females (39% and 29% respectively). However, the accidental deaths of females were more likely to involve benzodiazepines (28%) and antidepressants (23%) than those of males (21% and 11% respectively). The accidental deaths of females were less likely than males to involve other narcotics and hallucinogens (14% and 20% respectively). Alcohol was also present in combination with other drugs in 18% of accidental drug-induced deaths, although it was not the underlying cause of death.

22. The drugs used most commonly in suicides were benzodiazepines, antidepressants and opium, heroin and other opioids, which were involved in 28%, 28% and 20% of all suicides by drugs respectively. 4-Aminophenol derivatives such as paracetemol were more likely to be used by females who suicided than by males (13% and 9% respectively), while females were less likely than males to use benzodiazepines (25% and 31% respectively). Alcohol was also used in combination with other drugs in 13% of suicides by drugs, although it was not the underlying cause of death.

23. Consistent with the changing pattern of underlying drug-induced deaths, there was a substantial decrease in the total proportion of drug-induced deaths involving opium, heroin and other opioids, from 58% in 1999 to 31% in 2001. This decrease could be seen amongst both males and females (63% to 35% and 46% to 25% respectively). However, there was an overall increase in the proportion of drug-induced deaths involving methadone, from 8% in 1999 to 10% in 2001.

TABLE 1 - MAIN TYPES OF DRUGS CONTRIBUTING TO DRUG-INDUCED DEATHS (a), Australia, 2001, as a percentage of drug-induced deaths (b), by sex and intent

ACCIDENTAL

SUICIDE

EXAMPLE/COMMON NAME

MALES

FEMALES

MALES

FEMALES

%

%

%

%

T39.1 4-Aminophenol derivatives

Paracetemol

3

10

9

13

T40.0-40.2 Opium, heroin & other opioids

Heroin, morphine

39

29

22

17

T40.3 Methadone

Methadone

15

10

6

1

T40.4-40.9 Other narcotics & hallucinogens

Pethadine, cocaine, cannabis

20

14

10

5

T42.4 Benzodiazepines

Valium

21

28

31

25

T43.0-43.2 Antidepressants

Prozac

11

23

28

28

T43.3-43.5 Antipsychotics and neuroleptics

Promazine

1

5

4

7

T43.6 Psychostimulants

Amphetamines

8

7

2

1

T51 Alcohol (c)

Alcohol

18

18

14

11

Long term organ damage (d)

3

2

1

0

no.

no.

no.

no.

Total number of deaths

480

230

151

134

(a) Drugs mentioned on official records. These drugs may be the underlying cause, or may be a contributing part of a mixture of drugs which led to the death.(b) Death may be caused by more than one drug and therefore component percentages do not add to one hundred.(c) Alcohol is not included in the scope of poisoning in this article. Therefore alcohol is not the underlying cause of death, but taken in conjunction with other drugs, has led to these deaths.(d) Deaths attributed to long-term organ damage are drug-induced deaths where no poisons were identified in the body of the deceased at the time of post-mortem.

TABLE 2 - AVERAGE NUMBER OF DRUGS (a) PER DRUG-INDUCED DEATH, Australia, 2001, for main types of drugs (b), by sex and intent

ACCIDENTAL

SUICIDE

EXAMPLE/COMMON NAME

MALES

FEMALES

MALES

FEMALES

T39.1 4-Aminophenol derivatives

Paracetemol

2.5

4.0

3.1

3.6

T40.0-40.2 Opium, heroin & other opioids

Heroin, morphine

2.0

2.9

2.7

3.3

T40.3 Methadone

Methadone

2.2

2.5

2.4

3.5

T40.4-40.9 Other narcotics & hallucinogens

Pethadine, cocaine, cannabis

2.3

2.2

3.1

2.9

T42.4 Benzodiazepines

Valium

2.9

3.3

2.7

3.2

T43.0-43.2 Antidepressants

Prozac

3.1

3.0

2.5

2.7

T43.3-43.5 Antipsychotics and neuroleptics

Promazine

3.7

2.9

2.2

2.3

T43.6 Psychostimulants

Amphetamines

2.5

2.9

4.0

4.0

T51 Alcohol

Alcohol

2.5

2.8

2.9

3.3

Total (c)

1.7

1.9

1.8

1.8

(a) Drugs mentioned on official records. These drugs may be the underlying cause, or may be a contributing part of a mixture of drugs which lead to the death. Codes included are (T36-T50) Poisoning by Drugs,Medicaments and Biological substances and (T51) Toxic Effect of Alcohol.(b) Average number of drugs amongst deaths where each type of drug was mentioned on death certificate.(c) Includes all drug-induced deaths, even if no poison code was mentioned on death certificate.

24. Information contained in the preceding sections of this paper refers to deaths registered by the state and territory Registrars-General during the calendar years in question. The following graph compares drug-induced death rates by year of registration and year of occurrence (see Explanatory Notes). There is very little difference between year of registration and year of occurrence figures, as around 89% of drug-induced deaths occurring in a particular year are registered in that year. This compares to around 95% for all deaths. Delays in registration of drug-induced deaths are more likely due to coroner deliberations.

FIGURE 7 - DRUG-INDUCED DEATHS, YEAR OF REGISTRATION AND YEAR OF OCCURRENCE (a), Australia, 1991-2001

25. Years of potential life lost is a measure of premature mortality, and is calculated based on deaths between the ages of 1 and 75 years. There were 37,356 years of potential life lost due to drug-induced deaths for the 2001 registration year. Drug-induced deaths accounted for 0.8% of registered deaths of all ages, and 1.9% of deaths between the ages of 1 and 75 years. Because drug-induced deaths occur generally in younger age groups, they represented 4.5% of the total years of potential life lost from all causes. See Table 7 for more details.

9. SUMMARY TABLES

TABLE 3 - ALL DRUG-INDUCED DEATHS (a), 1991-2001, by age and sex

Year of

15 - 24

25 - 34

35 - 44

45 - 54

55 - 64

65 - 74

75 & over

Total (b)

registration

no.

no.

no.

no.

no.

no.

no.

no.

MALES

1991

95

195

130

47

23

23

15

529

1992

114

253

116

46

26

21

10

587

1993

97

231

140

52

23

15

8

566

1994

135

245

177

71

17

19

8

674

1995

145

325

218

74

28

18

11

822

1996

160

305

207

78

18

11

10

795

1997

162

332

279

74

23

17

10

902

1998

220

475

308

93

26

25

22

1,172

1999

228

488

333

114

38

20

21

1,244

2000

200

388

331

97

21

23

14

1,078

2001

101

217

171

86

41

17

19

657

FEMALES

1991

50

94

63

45

42

17

15

328

1992

50

102

63

52

30

21

23

344

1993

46

76

75

32

28

24

14

299

1994

44

91

85

52

21

24

16

336

1995

68

87

86

62

26

18

16

363

1996

47

87

96

66

21

16

12

347

1997

75

119

93

59

27

30

16

421

1998

74

105

123

66

27

31

42

473

1999

87

142

119

73

33

20

20

495

2000

70

118

142

59

50

27

21

491

2001

43

79

104

75

35

19

24

381

PERSONS

1991

145

289

193

92

65

40

30

857

1992

164

355

179

98

56

42

33

931

1993

143

307

215

84

51

39

22

865

1994

179

336

262

123

38

43

24

1,010

1995

213

412

304

136

54

36

27

1,185

1996

207

392

303

144

39

27

22

1,142

1997

237

451

372

133

50

47

26

1,323

1998

294

580

431

159

53

56

64

1,645

1999

315

630

452

187

71

40

41

1,739

2000

270

506

473

156

71

50

35

1,569

2001

144

296

275

161

76

36

43

1,038

(a) ICD-10 codes F11-F16, F19, F55, X40-X44, X60-X64, X85 and Y10-Y14.(b) Total includes under 15 years and age not stated.

TABLE 7 - YEARS OF POTENTIAL LIFE LOST (YPLL) (a), 1991-2001, drug-induced deaths and deaths due to all causes

Year of registration

Number of deaths (b)

Years of potential life lost (c)

Drug-induced deaths as a percentage of total

DRUG-INDUCED

ALL CAUSES

DRUG INDUCED

ALL CAUSES

DEATHS (b)

YPLL

no.

no.

no.

no.

%

%

1991

829

59,784

30,684

975,115

1.4

3.1

1992

898

60,386

33,812

968,959

1.5

3.5

1993

845

58,928

31,929

943,164

1.4

3.4

1994

987

59,683

37,709

937,848

1.7

4.0

1995

1,159

58,994

44,875

935,556

2.0

4.8

1996

1,121

58,914

43,817

930,280

1.9

4.7

1997

1,299

58,472

50,877

930,150

2.2

5.5

1998

1,584

56,782

62,810

911,642

2.8

6.9

1999

1,703

55,632

68,100

890,655

3.1

7.6

2000

1,536

54,232

60,969

864,591

2.8

7.1

2001

996

53,351

37,356

831,513

1.9

4.5

(a) YPLL measures the extent of premature mortality which is assumed to be any death occurring between ages 1 and 75 inclusive.(b) Deaths occurring between ages 1-75 years inclusive.(c) YPLL age-standardised to 2001 Australian population - see Technical Note in ABS publication 'Causes of Death, Australia 2001', cat. no. 3303.0.8